[PATCH 1/8] Fix for a regression that was introduced by earlier commit

Thomas Renninger
2009-04-17T14:22:14Z

From: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>

Regression resulted in the below error happened on systems with
software coordination where per_cpu acpi data will not be initiated for
secondary CPUs in a P-state domain.

BUG: unable to handle kernel NULL pointer dereference at
0000000000000020
IP: [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
PGD a7dd88067 PUD a7ccf5067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
CPU 0
Modules linked in: video output
Pid: 2091, comm: kondemand/0 Not tainted 2.6.30-rc2 #1 MP Server
RIP: 0010:[<ffffffff8021af75>] [<ffffffff8021af75>]
get_measured_perf+0x4a/0xf9
RSP: 0018:ffff880a7d56de20 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000046241a42b6 RCX: ffff88004d219000
RDX: 000000000000b660 RSI: 0000000000000020 RDI: 0000000000000001
RBP: ffff880a7f052000 R08: 00000046241a42b6 R09: ffffffff807639f0
R10: 00000000ffffffea R11: ffffffff802207f4 R12: ffff880a7f052000
R13: ffff88004d20e460 R14: 0000000000ddd5a6 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88004d200000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000020 CR3: 0000000a7f1bf000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kondemand/0 (pid: 2091, threadinfo ffff880a7d56c000, task
ffff880a7d4d18c0)
Stack:
ffff880a7f052078 ffffffff803efd54 00000046241a42b6 000000462ffa9e95
0000000000000001 0000000000000001 00000000ffffffea ffffffff8064f41a
0000000000000012 0000000000000012 ffff880a7f052000 ffffffff80650547
Call Trace:
[<ffffffff803efd54>] ? kobject_get+0x12/0x17
[<ffffffff8064f41a>] ? __cpufreq_driver_getavg+0x42/0x57
[<ffffffff80650547>] ? do_dbs_timer+0x147/0x272
[<ffffffff80650400>] ? do_dbs_timer+0x0/0x272
[<ffffffff802474ca>] ? worker_thread+0x15b/0x1f5
[<ffffffff8024a02c>] ? autoremove_wake_function+0x0/0x2e
[<ffffffff8024736f>] ? worker_thread+0x0/0x1f5
[<ffffffff80249f0d>] ? kthread+0x54/0x83
[<ffffffff8020c87a>] ? child_rip+0xa/0x20
[<ffffffff80249eb9>] ? kthread+0x0/0x83
[<ffffffff8020c870>] ? child_rip+0x0/0x20
Code: 99 a6 03 00 31 c9 85 c0 0f 85 c3 00 00 00 89 df 4c 8b 44 24 10 48
c7 c2 60 b6 00 00 48 8b 0c fd e0 30 a5 80 4c 89 c3 48 8b 04 0a <48> 2b
58 20 48 8b 44 24 18 48 89 1c 24 48 8b 34 0a 48 2b 46 28
RIP [<ffffffff8021af75>] get_measured_perf+0x4a/0xf9
RSP <ffff880a7d56de20>
CR2: 0000000000000020

Signed-off-by: Thomas Renninger <trenn@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: <cpufreq@vger.kernel.org>
---
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 15 ++++++++++-----
1 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 9d3af38..ed43734 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -68,11 +68,16 @@ struct acpi_cpufreq_data {
unsigned int max_freq;
unsigned int resume;
unsigned int cpu_feature;
- u64 saved_aperf, saved_mperf;
};

static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);

+struct acpi_msr_data {
+ u64 saved_aperf, saved_mperf;
+};
+
+static DEFINE_PER_CPU(struct acpi_msr_data, msr_data);
+
DEFINE_TRACE(power_mark);

/* acpi_perf_data is a pointer to percpu data. */
@@ -287,11 +292,11 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy,
return 0;

cur.aperf.whole = readin.aperf.whole -
- per_cpu(drv_data, cpu)->saved_aperf;
+ per_cpu(msr_data, cpu).saved_aperf;
cur.mperf.whole = readin.mperf.whole -
- per_cpu(drv_data, cpu)->saved_mperf;
- per_cpu(drv_data, cpu)->saved_aperf = readin.aperf.whole;
- per_cpu(drv_data, cpu)->saved_mperf = readin.mperf.whole;
+ per_cpu(msr_data, cpu).saved_mperf;
+ per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole;
+ per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole;

#ifdef __i386__
/*
--
1.6.0.2